The Bracken Bat Cave, located in southern Comal County, Texas, outside the city of San Antonio, is the summer home to the largest colony of bats in the world. Each year during summer, an estimated 20 million Mexican Free-tailed bats migrate from Mexico to Texas to give birth and raise their pups. While these bats take refuge all across the state, the largest congregation takes place at Bracken Cave.

Every night from March to October, these tiny creatures fly out of the 100-foot-wide crescent-shaped opening to feed. The bats’ exodus is slow at first as they linger at the cave’s lip, circling round and round inside before emerging. Over the next four hours, millions and millions of bats stream out of the cave in graceful swirls as they rise into the wide sky and dissipate in the distance. They spread out over a 60-mile radius from the cave at heights of up to 10,000 feet and over the next 8 to 12 hours feed on hundreds of tons of insects, such as moths and agricultural pests. Their emergence is so dense that it shows up on Doppler radar, according to TexasCoopPower.com. Those who have seen the bats’ nightly emergence have described the sound they generate as that of steadily falling rainstorm.

Besides tourists and bat lovers, a host of other creatures expectantly wait for their exit. Great Horned Owl and Harris’s Hawks scope out potential dinners from nearby trees, while skunks, raccoons, opossums and rattlesnakes lurk on the ground to strike low-flying bats from the air.

The Bracken bat colony consumes tons of insects each night and plays an important role in pest control, helping farmers control moths, beetles and insects that destroy corn, cotton and other crops. The Bracken site has had a significant role in Texas and US history. The cave was mined in the 1860s for guano (bat droppings) to manufacture black gunpowder, during the Civil War. The guano was later used as a rich fertilizer for croplands across the United States.

The bat cave sits upon private land owned by Bat Conservation International that owns 697 acres of undeveloped land around it. Access to the cave is restricted to protect the habitat of the resident bats, but evening guided tours to the cave are offered to watch the bats emerge from the cave.

There’s nothing like a road trip to really experience a country. From coastal highways and dizzying mountain passes, to scenic routes through national parks and bridges over great spans of water; roads are the circulatory system that connects a country. After an extensive search online, HU has compiled a list of some of the most beautiful, challenging and unforgettable roads in the world.

While hardly exhaustive, this list should provide great inspiration and bucket list fodder for those planning an upcoming trip.

1. Highway 1, Big Sur, California

State Route 1 (SR 1) is a major north-south state highway that runs along most of the Pacific coastline of the U.S. state of California. The highway is famous for running along some of the most beautiful coastlines in the USA, leading to its designation as an All-American Road.

Highway 1 enters the Big Sur region crossing the San Carpoforo Creek just south of the Monterey County line. For about 90 miles (140 km) from the San Carpoforo Creek to the Carmel River, the road winds and hugs the cliffs of Big Sur, passing various coastal parks in the area. The road also briefly leaves the coast for a few miles and goes through a redwood forest in the Big Sur River valley. This segment of the highway, built between 1919 and 1937, also crosses several historic bridges, including the scenic Bixby Creek Bridge shown above.

2. Furka Pass, Switzerland

Furka Pass (el. 2429 m.) is a high mountain pass in the Swiss Alps connecting Gletsch, Valais with Realp, Uri. The Furka Pass was used as a location in the James Bond film Goldfinger.

3. The Atlantic Road, Norway

Opened on July 7, 1989, the Atlantic Road is a National Tourist Route and was honoured as Norway’s Construction of the Century in 2005. The Atlantic is an 8.3 kilometer (5.2 miles) section of Country Road 64 which runs between the towns of Kristiansund and Molde, the two main population centres in the county of More og Romsdal in Fjord, Norway. The road is built on several small islands and skerries, which are connected by several causeways, viaducts and eight bridges. For more information check out this featured post on the Sifter.

4. White Rim Road, Canyonlands National Park, Utah

The 100-mile White Rim Road loops around and below the Island mesa top and provides expansive views of the surrounding area. Trips usually take two to three days by four-wheel-drive vehicle or three to four days by mountain bike. All vehicles and bikes must remain on roads. ATVs and non-street legal dirt bikes are not permitted. Pets are also not permitted, even in vehicles.

Under favorable weather conditions, the White Rim Road is considered moderately difficult for high-clearance, four-wheel-drive vehicles. The steep, exposed sections of the Shafer Trail, Lathrop Canyon Road, Murphy’s Hogback, Hardscrabble Hill, and the Mineral Bottom switchbacks make the White Rim loop a challenging mountain bike ride, and require extreme caution for both vehicles and bikes during periods of inclement weather.

5. Tianmen Mountain Road, Hunan, China

Tianmen Mountain is a mountain located within Tianmen Mountain National Park, Zhangjiajie, in northwestern Hunan Province, China. A cable car operates from nearby Zhangjiajie railway station to the top of the mountain. It features 98 cars and a total length of 7,455 meters and an ascent of 1,279 meters. The highest gradient is an unusual 37 degrees. There is also an 11 km road with 99 bends that reaches the top of the mountain and takes visitors to Tianmen cave, a natural hole in the mountain at a height of 131.5 meters.

6. Seven Mile Bridge, Florida Keys

The Seven Mile Bridge is a famous bridge in the Florida Keys, in Monroe County, Florida, United States. It connects Knight’s Key (part of the city of Marathon, Florida) in the Middle Keys to Little Duck Key in the Lower Keys. Among the longest bridges in existence when it was built, it is one of the many bridges on US 1 in the Keys, where the road is called the Overseas Highway.

7. Chapman’s Peak Drive, Cape Town, South Africa

Chapman’s Peak Drive winds it way between Noordhoek and Hout Bay on the Atlantic Coast of the south-western tip of South Africa. The 9km route, with its 114 curves, skirts the rocky coastline of Chapman’s Peak (593m). The drive is affectionately known as “Chappies” and offers stunning 180° views with many areas along the route where you can stop and take in the exquisite scenery.

8. Stelvio Pass, Eastern Alps, Italy

The Stelvio Pass, located in Italy, at 2757 m (9045 feet) is the highest paved mountain pass in the Eastern Alps, and the second highest in the Alps, slightly below the Col de l’Iseran (2770 m, 9088 feet). Stelvio was also picked by the British automotive show Top Gear as its choice for the “greatest driving road in the world”, although their search was concentrated only in Europe. This conclusion was reached after the team went in search of a road that would satisfy every “petrolhead’s” driving fantasies in the premiere of the show’s 10th season. Top Gear later decided that the Transfăgărăşan Highway in Romania was possibly a superior driving road.

9. Col de Turini, France

The Col de Turini (el. 1607 m) is a high mountain pass in the Alps in the department of Alpes-Maritimes in France. It lies near Sospel, between the communes of Moulinet and La Bollène-Vésubie in the Arrondissement of Nice. It is famous for a stage of the Monte Carlo Rally which is held on the tight road with its many hairpin turns. The Col de Turini has also featured three times in the Tour de France (1948, 1950 and 1975) averaging 7.2% over 15.3 km when approached from the East starting at the valley of the river Vésubie.

10. Guoliang Tunnel Road, China

The Guoliang Tunnel is carved along the side of and through a mountain in China. The tunnel is located in the Taihang Mountains which are situated in the Henan Province of China. If you want to get there, you should start your trip in Xinxiang. Leave the city by driving north on Huanyu Avenue (the S229). After 13 miles you’ll enter the town of Huixian. Stay on the S229 for 15 miles more until you reach the junction with the S228. Turn left here and keep following the S229. After 8 miles you reach the village of Nanzhaizen. Turn left again and follow directions to Guoliang, 8 miles further.

11. Denali Highway, Alaska

Denali Highway (Alaska Route 8) is a lightly traveled, mostly gravel highway in the U.S. state of Alaska. It leads from Paxson on the Richardson Highway to Cantwell on the Parks Highway. Opened in 1957, it was the first road access to Denali National Park (then known as Mount McKinley National Park). The Denali is 135 miles (217 km) in length.

12. Karakoram Highway, China/Pakistan

The Karakoram Highway (KKH) is the highest paved international road in the world. It connects China and Pakistan across the Karakoram mountain range, through the Khunjerab Pass, at an elevation of 4,693 m/15,397 ft. It connects China’s Xinjiang region with Pakistan’s Gilgit–Baltistan and Khyber Pakhtunkhwa regions and also serves as a popular tourist attraction. Due to its high elevation and the difficult conditions in which it was constructed, it is also referred to as the “Eighth Wonder of the World.” The Karakorum Highway is known informally as the KKH, and — within Pakistan — officially as the N-35; within China, officially as China National Highway 314 (G314).

13. Great Ocean Road, Australia

The Great Ocean Road is an Australian National Heritage listed 243-kilometre (151 mi) stretch of road along the south-eastern coast of Australia between the Victorian cities of Torquay and Warrnambool. The road was built by returned soldiers between 1919 and 1932, and is the world’s largest war memorial; dedicated to casualties of World War I. It is an important tourist attraction in the region, which winds through varying terrain alongside the coast, and provides access to several prominent landmarks; including the nationally significant Twelve Apostles limestone stack formations.

14. Sani Pass, KwaZulu-Natal, South Africa

Sani Pass is located in the western end of KwaZulu-Natal province of South Africa on the road between Underberg and Mokhotlong, Lesotho. Sani Pass is a notoriously dangerous road that requires the use of a 4×4 vehicle. The pass is approximately 9 km in length and requires above average driving experience. While South African immigration at the bottom of the pass prohibits vehicles deemed unsuitable for the journey, the Lesotho border agents at the top generally allow vehicles of all types to attempt the descent. Border between the two countries closes at 4:00 pm every day and the Pass is often closed due to weather conditions, especially during winter.

15. Ruta 40, Argentina

National Route 40 or RN40 (often called Ruta 40), is a route in western Argentina, stretching from Cabo Virgenes in Santa Cruz Province in the south to La Quiaca in Jujuy Province in the north, running parallel to the Andes mountains. The southern part of the route, a largely paved road through sparsely populated territory, has become a well-known adventure tourism journey.

Route 40 is the longest route in Argentina and one of the largest in the world (along with the U.S. Route 66 and the Stuart Highway in Australia. It is more than 5,000 km (3,107 mi) long and crosses 20 national parks, 18 major rivers, 27 passes on the Andes, and goes up to 5,000 m (16,404 ft) above sea level in Abra del Acay in Salta.

16. Going-to-the-Sun-Road, Glacier National Park, Montana

Going-to-the-Sun Road was completed in 1932 and is a spectacular 50 mile, paved two-lane highway that bisects Glacier National Park east and west. It spans the width of the Park, crossing the Continental Divide at 6,646-foot-high Logan Pass. It passes through almost every type of terrain in the park, from large glacial lakes and cedar forests in the lower valleys to windswept alpine tundra atop the pass. Scenic viewpoints and pullouts line the road. In 1983 Going-To-The-Sun Road was included in the National Register of Historic Places and in 1985 was made a National Historic Civil Engineering Landmark.

17. Dadès Gorges, High Atlas, Morocco

Carved over the centuries by the Dades River, the Dades Gorge is now a very popular destination for travellers in Morocco. Travellers in 4WD (with a guide) can follow a mountain loop (at certain times of the year), following Dades Gorge as far north as Agoudal, then turning south to head for Todra Gorge. It can be accessed from the small town of Boumaine which lies 116 km northeast of Ouarzazate and 53 km from Tinerhir. A sealed road runs for 63 km through the Gorge as far as Msemrir, after that 4WD is necessary. The best time to visit the lower valleys is from March to May and the mountains are best from May to July.

18. U.S. Route 550 ‘The Million Dollar Highway, Colorado

U.S. Route 550 is a spur of U.S. Highway 50 that runs from Bernalillo, New Mexico to Montrose, Colorado in the western United States. The section from Silverton to Ouray is frequently called the Million Dollar Highway. The Million Dollar Highway stretches for about 25 miles (40 km) in western Colorado and follows the route of U.S. 550 between Silverton and Ouray, Colorado. It is part of the San Juan Skyway Scenic Byway. Between Durango and Silverton the Skyway loosely parallels the Durango and Silverton Narrow Gauge Railroad.

Though the entire stretch has been called the Million Dollar Highway, it is really the twelve miles (19 km) south of Ouray through the Uncompahgre Gorge to the summit of Red Mountain Pass which gains the highway its name. This stretch through the gorge is challenging and potentially hazardous to drive; it is characterized by steep cliffs, narrow lanes, and a lack of guardrails; the ascent of Red Mountain Pass is marked with a number of hairpin curves used to gain elevation, and again, narrow lanes for traffic—many cut directly into the sides of mountains.

19. Trollstigen, Rauma, Norway

Trollstigen (English: Trolls’ Ladder) is a serpentine mountain road in Rauma, Norway, part of Norwegian National Road 63 connecting Åndalsnes in Rauma and Valldal in Norddal. It is a popular tourist attraction due to its steep incline of 9% and eleven hairpin bends up a steep mountain side. Trollstigen was opened on July 31, 1936, by King Haakon VII after 8 years of construction. During the top tourist season about 2,500 vehicles pass daily.

The road is narrow with many sharp bends, and although several bends have been widened during the years 2005 to 2012, vehicles over 12.4 metres long are prohibited from driving the road. At the 700 metres plateau there is a car park and several viewing balconies overlooking the bends and the Stigfossen waterfall. Trollstigen is closed during autumn and winter. A normal opening season stretches from mid-May to October, but may sometimes be shorter or longer due to changes in the weather conditions.

20. The Amalfi Coast, Italy

The Amalfi Coast is widely considered Italy’s most scenic stretch of coastline, a landscape of towering bluffs, pastel-hued villages terraced into hillsides, corniche roads, luxuriant gardens, and expansive vistas over turquoise waters and green-swathed mountains. Deemed by UNESCO “an outstanding example of a Mediterranean landscape,” the coast was awarded a coveted spot on the World Heritage list in 1997. The Amalfi Coast lies along the southern flanks of the Sorrento Peninsula, a cliff-edged promontory that wanders out from the mainland at the southern end of the Bay of Naples.

21. Transfăgărășan, Romania

The Transfăgărășan or DN7C is the second-highest paved road in Romania. Built as a strategic military route, the 90 km of twists and turns run north to south across the tallest sections of the Southern Carpathians, between the highest peak in the country, Moldoveanu, and the second highest, Negoiu. The road connects the historic regions of Transylvania and Wallachia, and the cities of Sibiu and Pitești.

The road climbs to 2,034 metres altitude. The most spectacular route is from the North. It is a winding road, dotted with steep hairpin turns, long S-curves, and sharp descents. Top Gear host, Jeremy Clarkson, had said about Transfăgărășan that, “this is the best road… in the world” – a title the program’s presenters had previously given to the Stelvio Pass in Italy.

Jacob's Well in Texas Hill Country is a perennial karstic spring located on the bed of Cypress Creek in Wimberley. The mouth of the well is four meters in diameter through which thousands of gallons of water surges up per minute feeding Cypress Creek that flows through Wimberley, sustaining Blue Hole and the Blanco River, recharging the Edwards Aquifer, and finally replenishing estuaries in the Gulf of Mexico.

The well was first discovered in the 1850s when a couple of early settlers followed Cypress Creek to its source. They described the crevice in the creek bed which was overflowing with an abundance of clear, cool water as "like unto a well in Bible times." Since then, the location has been a beloved swimming hole for generations, a gathering place for Native Americans and early settlers, and a rich habitat for aquatic species. It is also a popular diving spot for thrill seekers despite the fact that at least eight divers have lost their lives here over the years.

Jacob's Well is one of the longest underwater caves in Texas. From the opening in the creek bed, the cave descends vertically for about ten meters, then continues downward at an angle through a series of silted chambers separated by narrow restrictions, finally reaching a depth of forty meters.

Through the years, many have successfully explored the first and second chambers of the well. The first chamber is a straight drop to about 30 feet; then it angles down to 55 feet. Nourished by the rays of sunlight that penetrate the crystal water, this cavern area is bright and is home to algae and wildlife. The second chamber is a long funnel to 80 feet, where there is a restricted opening to the third chamber. Inside the second chamber is a false chimney, which appears to be a way out of the well but has trapped at least one diver. The third chamber is a small room with a floor of unstable gravel. Divers must inflate water wings to navigate this chamber successfully, trying not to stir up silt or dislodge the gravel.

The passage into the fourth chamber is very tight. The few who have seen the fourth chamber say it is "virgin cave" with fantastic limestone formations and no gravel. Covering the bottom is fine silt that can totally obscure vision when kicked up by one misstep.

Ironically, there was a time when it was impossible to descend into Jacob's Well. "There's a picture of me at 3 years old at Jacob's Well in the family album," recalls 79-year-old historian Dorothy Wimberley Kerbow. "My dad would throw me into the well. You couldn't sink down because the spring would just bubble you up with such force."

Kerbow recalls that she and her friends would often visit Jacob's Well in the 1950s, and it was impossible to go more than two feet below the surface due to the force of the spring.

In 1924, Jacob’s Well was measured to have a flow of one hundred and seventy gallons per second (six hundred and forty liters per second) discharging water six feet into the air. Over the years, the well’s flow had diminished allowing divers to reach the deepest chambers. The spring ceased flowing for the first time in recorded history in 2000, and again in 2008.

The first time the spring stopped flowing, the event was considered by many as symbolic of the region's increasing water shortage and quality problems. “It was a wake-up call for everyone,” recalls landowner David Baker. “We don't want it to turn into Jacob's Cave."

David Baker has given up his home to form the Jacob’s Well Natural Area to restore and protect this sensitive area for future generations.

UTA Flight 772 was a scheduled flight operating from Brazzaville in the People's Republic of Congo to Paris in France. On Tuesday, September 19th, 1989, six Libyan terrorists boarded the plane DC-10 and ignited a suitcase bomb on its way to Paris from Brazzaville. UTA Flight 772 broke up over the Sahara Desert near the towns of Bilma and Ténéré in Niger. All 155 passengers and 15 crew members died. On the 18th anniversary of the disaster, families of the victims gathered at the crash site to build a memorial. Lying in the middle of the Sahara, it is one of the least accessible memorial in the world.

The memorial consist of a life-sized silhouette of the aircraft created using dark stones set into the sand. The silhouette lies inside a circle more than 200ft in diameter. Surrounding this circle are 170 broken mirrors, representing those who died, and arrows marking the points of the compass. At the northern point, part of the right wing of the actual DC-10 has been erected as a monument, with a plaque commemorating the victims.

Due to the remote resting place of the wreck, the wreckage is still scattered around the area. Trucks were driven almost 70 km out to transport countless stones to place at the crash site. After two months of grueling work in a brutal climate, the monument was complete. The memorial was financed by a 170-million-dollar compensation fund provided by the Libyan government.

The memorial can be viewed in Google Maps at the coordinates 16°51’53″N 11°57’13″E.